Stabilization of oxidation-sensitive or UV-sensitive active ingredients

ABSTRACT

Cosmetic and dermatological formulations comprising at least one hydrophilic active ingredient and at least one dialkyl naphthalate which is characterized by the structural formula  
                 
 
     in which R 1  and R 2 , independently of one another, are selected from the group of branched and unbranched alkyl groups having 6 to 24 carbon atoms, have been found to be stable and effective, particularly in moisturizing the skin or protection the skin from skin aging.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This is a continuation application of PCT/EP02/09374, filed Aug.22, 2002, which is incorporated herein by reference in its entirety, andalso claims the benefit of German Priority Application No. 101 41 472.2,filed Aug. 29, 2001.

FIELD OF THE INVENTION

[0002] The present invention relates to the use of alkyl naphthalatesfor improving the effectiveness of hydrophilic active ingredients incosmetic or dermatological preparations. The present inventionpreferably relates to the use of alkyl naphthalates for improving theeffectiveness of water-soluble skincare substances—such as, for example,biotin, carnitine, flavonoids, such as alpha-glucosylrutin, ascorbicacid and the like—and to cosmetic or dermatological preparations inwhich such active ingredients can be stored in stable form over a longperiod and which represent a good transport means for these activeingredients.

BACKGROUND OF THE INVENTION

[0003] Cosmetic skincare serves primarily to strengthen or restore thenatural function of the skin as a barrier against environmentalinfluences (e.g. dirt, chemicals, microorganisms) and against the lossof substances intrinsic to the body (as well as water, also naturalfats, electrolytes, etc.).

[0004] Impairment of this function may lead to increased resorption oftoxic or allergenic substances or to attack by microorganisms, resultingin toxic or allergic skin reactions.

[0005] A further aim of skincare is to compensate for the loss by theskin of sebum and water caused by daily washing. This is particularlyimportant when the natural regeneration ability is inadequate.Furthermore, skincare products should protect against environmentalinfluences, in particular against sun and wind, and delay skin ageing.

[0006] Chronological skin ageing is caused, for example, by endogenous,genetically determined factors. As a result of ageing, the followingstructural damage and functional disorders, which can also fall underthe term “senile xerosis”, arise in the epidermis and dermis:

[0007] a) dryness, roughness and formation of dryness wrinkles,

[0008] b) itching and

[0009] c) reduced refatting by sebaceous glands (e.g. after washing).

[0010] Exogenous factors, such as UV light and chemical noxae, can havea cumulative effect and, for example, accelerate or supplement theendogenous ageing processes. In the epidermis and dermis, for example,the following structural damage and functional disorders may arise inthe skin in particular as a result of exogenous factors; these are morefar-reaching than the degree and quality of the damage in the case ofchronological ageing:

[0011] d) visible vascular dilations (teleangiectases, couperosis);

[0012] e) flaccidity and formation of wrinkles;

[0013] f) local hyperpigmentation, hypopigmentation and abnormalpigmentation (e.g. age spots) and

[0014] g) increased susceptibility to mechanical stress (e.g. cracking).

SUMMARY OF THE INVENTION

[0015] The present invention relates in particular to products for thecare of skin aged in a natural way, and for the treatment of theconsequential damage of photoageing in particular of the phenomenalisted under a) to g), preferably those which are characterized byincreased effectiveness.

[0016] In particular, the present invention relates to cosmeticpreparations with effective protection against harmful oxidationprocesses in the skin, but also for the protection of cosmeticpreparations themselves or for the protection of the constituents ofcosmetic preparations against harmful oxidation processes.

[0017] The present invention further relates to antioxidants, preferablythose which are used in skincare cosmetic or dermatologicalpreparations. In particular, the invention also relates to cosmetic anddermatological preparations comprising such antioxidants. In a preferredembodiment, the present invention relates to cosmetic and dermatologicalpreparations for the prophylaxis and treatment of cosmetic ordermatological changes in the skin, such as e.g. skin ageing, inparticular skin ageing caused by oxidative processes.

[0018] In addition, the present invention relates to active ingredientsand preparations comprising such active ingredients for the cosmetic anddermatological treatment or prophylaxis of erythematous, inflammatory,allergic or autoimmunoreactive phenomena, in particular dermatoses.

[0019] In a further advantageous embodiment, the present inventionrelates to active ingredient combinations and preparations which servefor the prophylaxis and treatment of photosensitive skin, in particularof photodermatoses.

[0020] The harmful effect of the ultraviolet part of solar radiation onthe skin is generally known. The rays have different effects on the skinorgan depending on their particular wavelength: so-called UV-C radiationwith a wavelength below 290 nm is absorbed by the ozone layer in theearth's atmosphere and therefore is of no physiological importance. Bycontrast, rays in the range between 290 nm and 320 nm, the so-calledUV-B region, cause erythema, simple sunburn or even burns of greater orlesser severity. A maximum for the erythema activity of sunlight isstated as being the relatively narrow range around 308 nm.

[0021] Numerous compounds are known for protecting against UV-Bradiation, examples thereof being derivatives of 3-benzylidenecamphor,of 4-aminobenzoic acid, of cinnamic acid, of salicylic acid, ofbenzophenone, and of triazine.

[0022] It has long been incorrectly assumed that the long-wave UV-Aradiation with a wavelength between 320 nm and 400 nm has only anegligible biological effect. However, it has now been proven bynumerous studies that UV-A radiation is far more hazardous than UV-Bradiation with regard to the triggering of photodynamic, specificallyphototoxic, reactions and chronic changes in the skin. The harmfuleffect of UV-B radiation can also be further intensified by UV-Aradiation.

[0023] Thus, it has been proven, inter alia, that even UV-A radiationunder entirely normal everyday conditions is sufficient to damage withina short time the collagen and elastin fibers which are of essentialimportance for the structure and firmness of the skin. This results inchronic photoinduced changes in the skin—the skin “ages” prematurely.The clinical appearance of skin aged by light includes, for example,wrinkles and lines and an irregular, furrowed relief. In addition, theareas affected by photoinduced skin aging may have irregularpigmentation. The formation of brown spots, keratoses and evencarcinomas or malignant melanomas is also possible. Skin agedprematurely by everyday exposure to UV is additionally characterized bya lower activity of the Langerhans cells and a slight chronicinflammation.

[0024] It is therefore of fundamental importance that cosmetic anddermatological photoprotective preparations offer adequate protectionboth against UV-B and also against UV-A radiation.

[0025] The prior art also recognizes a series of different efficient,hydrophilic skincare active ingredients—such as, for example, biotin,carnitine, flavonoids, such as alpha-glucosylrutin, ascorbic acid andthe like—whose use in cosmetic and dermatological formulations, inparticular in formulations of the oil-in-water type, is very desirable.Sadly, however, such substances are often very unstable meaning that,particularly in aqueous media, they rapidly decompose and in so doinglose their effectiveness. Moreover, since they are poorly soluble inoil, an effective concentration of hydrophilic active ingredients canonly be achieved with difficulty even in nonaqueous systems.

[0026] A further object of the present invention was therefore, inparticular, to overcome the disadvantages of the prior art and toprotect hydrophilic skincare active ingredients, in particular biotin,carnitine, flavonoids, such as alpha-glucosylrutin, and ascorbic acid,from decomposition and thus to increase their effectiveness, preferablyin cosmetic or dermatological preparations. It was also an object tofind cosmetic or dermatological preparations in which hydrophilicskincare active ingredients can be stored in a stable manner over a longperiod and which represent a good transport means for these activeingredients.

[0027] It was surprising and could not have been foreseen by the personskilled in the art that

[0028] cosmetic and dermatological formulations containing at least onehydrophilic active ingredient, characterized in that they comprise atleast one dialkyl naphthalate which is characterized by the structuralformula

[0029] in which R¹ and R², independently of one another, are chosen fromthe group of branched and unbranched alkyl groups having 6 to 24 carbonatoms, overcome the disadvantages of the prior art.

[0030] As well as one or more oil phases, the preparations within themeaning of the present invention may preferably additionally compriseone or more water phases and be present, for example, in the form ofW/O, O/W, W/O/W or O/W/O emulsions. Such formulations may preferablyalso be a microemulsion, a PIT emulsion, a solids emulsions (i.e. anemulsion which is stabilized by solids, e.g. a Pickering emulsion), asprayable emulsion or a hydrodispersion.

[0031] The preparations according to the invention are entirelysatisfactory preparations in every respect which are not restricted tothe limited choice of raw materials. Accordingly, they are veryparticularly suitable for use as bases for preparation forms withdiverse application purposes. The preparations according to theinvention exhibit very good sensory and cosmetic properties, such as,for example, extensibility on the skin or the ability to absorb into theskin, and are further distinguished by very good active ingredienteffectiveness coupled with excellent skincare data.

[0032] It could not have been foreseen by the person skilled in the artthat the use of alkyl naphthalates would better stabilize hydrophilicactive ingredients against decomposition. In addition, the use accordingto the invention can surprisingly considerably increase the stability ofhydrophilic active ingredients in water-containing cosmetic ordermatological formulations compared with the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] The invention therefore also provides for the use of at least onedialkyl naphthalate which is characterized by the structural formula

[0034] in which R¹ and R², independently of one another, are chosen fromthe group of branched and unbranched alkyl groups having 6 to 24 carbonatoms, for improving the effectiveness and increasing the stability ofhydrophilic active ingredients in cosmetic or dermatologicalpreparations.

[0035] Advantageous hydrophilic active ingredients which (individuallyor in any combinations with one another) are stabilized by the useaccording to the invention in an excellent manner are those listedbelow:

[0036] biotin

[0037] carnitine and derivatives

[0038] creatine and derivatives

[0039] folic acid

[0040] pyridoxine

[0041] niacinamide

[0042] polyphenols (in particular flavonoids, very particularlyalpha-glucosylrutin)

[0043] ascorbic acid and derivatives

[0044] Hamamelis

[0045] Aloe Vera

[0046] panthenol

[0047] amino acids.

[0048] Particularly advantageous hydrophilic active ingredients for thepurposes of the present invention are also water-soluble antioxidants,such as, for example, vitamins.

[0049] The amount of hydrophilic active ingredients (one or morecompounds) in the preparations is preferably 0.0001 to 10% by weight,particularly preferably 0.001 to 5% by weight, based on the total weightof the preparation.

[0050] For the purposes of the present invention, dialkyl naphthalatesin which R¹ and/or R² represent branched alkyl groups having 6 to 10carbon atoms are advantageous. For the purposes of the presentinvention, very particular preference is given to diethylhexylnaphthalate, which is available, for example, under the trade nameHallbrite TQ™ from CP Hall or Corapan TQ™ from H&R.

[0051] According to the invention, cosmetic or dermatologicalpreparations advantageously comprise 0.001 to 30% by weight, preferably0.01 to 20% by weight, very particularly preferably 1 to 15% by weight,of one or more dialkyl naphthalates.

[0052] The cosmetic or dermatological photoprotection formulationsaccording to the invention can have the customary composition and beused for cosmetic or dermatological photoprotection, in addition for thetreatment, care and cleansing of the skin and/or of the hair and as amake-up product in decorative cosmetics.

[0053] Depending on their formulation, cosmetic or topicaldermatological compositions for the purposes of the present inventionmay be used, for example, as skin protection cream, cleansing milk, dayor night cream etc. It is in some cases possible and advantageous to usethe compositions according to the invention as a basis forpharmaceutical formulations.

[0054] For use, the cosmetic and dermatological preparations are appliedto the skin and/or the hair in a sufficient amount in the mannercustomary for cosmetics.

[0055] The cosmetic and dermatological preparations according to theinvention can comprise cosmetic auxiliaries as are customarily used insuch preparations, e.g. preservatives, preservation helpers,bactericides, perfumes, substances to prevent foaming, dyes, pigmentswhich have a coloring action, thickeners, moisturizing and/or humectantsubstances, fillers which improve the feel of the skin, fats, oils,waxes or other customary constituents of a cosmetic or dermatologicalformulation, such as alcohols, polyols, polymers, foam stabilizers,electrolytes, organic solvents or silicone derivatives.

[0056] Advantageous preservatives for the purposes of the presentinvention are, for example, formaldehyde donors (such as e.g. DMDMhydantoin, which is available, for example, under the trade nameGlydant™ from Lonza), iodopropyl butylcarbamates (e.g. those availableunder the trade names Glycacil-L, Glycacil-S from Lonza, and/or DekabenLMB from Jan Dekker), parabens (i.e. p-hydroxybenzoic alkyl esters, suchas methyl, ethyl-, propyl- and/or butylparaben), phenoxyethanol,ethanol, benzoic acid and the like. According to the invention, thepreservative system usually also advantageously includes preservationhelpers, such as, for example, octoxyglycerol, glycine soya etc. aswell.

[0057] Particularly advantageous preparations are also obtained whenantioxidants are used as additives or active ingredients. According tothe invention, the preparations advantageously comprise one or moreantioxidants. Favorable, but nevertheless optional antioxidants whichmay be used are all antioxidants customary or suitable for cosmeticand/or dermatological applications.

[0058] The amount of antioxidants (one or more compounds) in thepreparations is preferably 0.001 to 30% by weight, particularlypreferably 0.05 to 20% by weight, in particular 0.1 to 10% by weight,based on the total weight of the preparation.

[0059] If vitamin E and/or derivatives thereof are the antioxidant orantioxidants, it is advantageous to choose their respectiveconcentrations from the range from 0.001 to 10% by weight, based on thetotal weight of the formulation.

[0060] If vitamin A or vitamin A derivatives, or carotenes orderivatives thereof are the antioxidant or antioxidants, it isadvantageous to choose their respective concentrations from the rangefrom 0.001 to 10% by weight, based on the total weight of theformulation.

[0061] It is particularly advantageous when the cosmetic preparationsaccording to the present invention comprise further cosmetic ordermatological active ingredients, preferred active ingredients beingantioxidants which can protect the skin against oxidative stress.

[0062] Advantageous further active ingredients are natural activeingredients and/or derivatives thereof, such as e.g. ubiquinones,retinoids, carotenoids, creatine, taurine and/or β-alanine.

[0063] Formulations according to the invention, which comprise e.g.known antiwrinkle active ingredients, such as flavone glycosides (inparticular α-glycosylrutin), coenzyme Q10, vitamin E and/or derivativesand the like, are particularly advantageously suitable for theprophylaxis and treatment of cosmetic or dermatological changes in skin,as arise, for example, during skin aging (such as, for example, dryness,roughness and formation of dryness wrinkles, itching, reduced refatting(e.g. after washing), visible vascular dilations (teleangiectases,couperosis), flaccidity and formation of wrinkles and lines, localhyperpigmentation, hypopigmentation and abnormal pigmentation (e.g. agespots), increased susceptibility to mechanical stress (e.g. cracking)and the like). In addition, they are advantageously suitable against theappearance of dry or rough skin.

[0064] The water phase of the preparations according to the inventioncan advantageously comprise customary cosmetic auxiliaries, such as, forexample, alcohols, in particular those of low carbon number, preferablyethanol and/or isopropanol, diols or polyols of low carbon number, andethers thereof, preferably propylene glycol, glycerol, ethylene glycol,ethylene glycol monoethyl or monobutyl ether, propylene glycolmonomethyl, monoethyl or monobutyl ether, diethylene glycol monomethylor monoethyl ether and analogous products, polymers, foam stabilizers,electrolytes, and in particular one or more thickeners which mayadvantageously be chosen from the group consisting of silicon dioxide,aluminum silicates, polysaccharides or derivatives thereof, e.g.hyaluronic acid, xanthan gum, hydroxypropylmethylcellulose, particularlyadvantageously from the group of polyacrylates, preferably apolyacrylate from the group of so-called carbopols, for example Carbopol980, 981, 1382, 2984, 5984, in each case individually or in combination.

[0065] Also advantageous are copolymers of C₁₀₋₃₀-alkyl acrylates andone or more monomers of acrylic acid, of methacrylic acid or estersthereof which are crosslinked with an allyl ether of sucrose or an allylether of pentaerythritol.

[0066] Compounds which bear the INCI name “Acrylates/C₁₀₋₃₀ AlkylAcrylate Crosspolymer” are advantageous. Those available under the tradenames Pemulen TR1 and Pemulen TR2 from B. F. Goodrich Company areparticularly advantageous.

[0067] Compounds which bear the INCI name AmmoniumAcryloyidimethyltaurate-Ninylpyrrolidone copolymers are advantageous.According to the invention, the AmmoniumAcryloyldimethyltaurate/Vinylpyrrolidone copolymers advantageously havethe empirical formula [C₇H₁₆N₂SO₄]_(n)[C₆H₉NO]_(m), corresponding to astatistical structure as follows

[0068] Preferred species for the purposes of the present invention arelisted in Chemical Abstracts under the Registry numbers 58374-69-9,13162-05-5 and 88-12-0 and are available under the trade nameAristoflex® AVC from Clariant GmbH.

[0069] Also advantageous are copolymers/crosspolymers comprisingAcryloyldimethyl Taurate, such as, for example, Simugel® EG or Simugel®EG from Seppic S.A.

[0070] Moisturizers can also preferably be used.

[0071] Moisturizers is the term used for substances or mixtures ofsubstances which, following application or distribution on the surfaceof the skin, confer on cosmetic or dermatological preparations theproperty of reducing the moisture loss by the horny layer (also calledtransepidermal water loss (TEWL)) and/or have a positive influence onthe hydration of the horny layer.

[0072] Advantageous moisturizers for the purposes of the presentinvention are, for example, glycerol, lactic acid and/or lactates, inparticular sodium lactate, butylene glycol, propylene glycol,biosaccaride gum-1, glycine soya, ethylhexyloxyglycerol,pyrrolidonecarboxylic acid and urea. In addition, it is particularlyadvantageous to use polymeric moisturizers from the group ofwater-soluble and/or water-swellable and/or water-gellablepolysaccharides. Particularly advantageous are, for example, hyaluronicacid, chitosan and/or a fucose rich polysaccharide which is listed inChemical Abstracts under the Registry number 178463-23-5 and isavailable, for example, under the name Fucogel®1000 from SOLABIA S.A.

[0073] The cosmetic or dermatological preparations according to theinvention can also advantageously, but not necessarily, comprise fillerswhich, for example, further improve the sensory and cosmetic propertiesof the formulations and, for example, bring about or intensify a velvetyor silky feel on the skin. Advantageous fillers for the purposes of thepresent invention are starch and starch derivatives (such as tapiocastarch, distarch phosphate, aluminum or sodium starch octenylsuccinateand the like), pigments which primarily have neither a UV filter effectnor a coloring effect (such as e.g. boron nitride etc.) and/or Aerosils®(CAS No. 7631-86-9).

[0074] The oil phase of the formulations according to the invention isadvantageously chosen from the group of polar oils, for example from thegroup of lecithins and of fatty acid triglycerides, namely thetriglycerol esters of saturated and/or unsaturated, branched and/orunbranched alkanecarboxylic acids with a chain length of from 8 to 24,in particular 12 to 18, carbon atoms. The fatty acid triglycerides can,for example, advantageously be chosen from the group of synthetic,semisynthetic and natural oils, such as e.g. cocoglyceride, olive oil,sunflower oil, soybean oil, peanut oil, rapeseed oil, almond oil, palmoil, coconut oil, castor oil, wheatgerm oil, grapeseed oil, thistle oil,evening primrose oil, macadamia nut oil and the like.

[0075] Also advantageous according to the invention are e.g. naturalwaxes of animal and vegetable origin, such as, for example beeswax andother insect waxes, and berry wax, shea butter and/or lanolin (woolwax).

[0076] Further advantageous polar oil components for the purposes of thepresent invention may also be chosen from the group of esters ofsaturated and/or unsaturated, branched and/or unbranchedalkanecarboxylic acids with a chain length of from 3 to 30 carbon atomsand saturated and/or unsaturated, branched and/or unbranched alcoholswith a chain length of from 3 to 30 carbon atoms, and from the group ofesters of aromatic carboxylic acids and saturated and/or unsaturated,branched and/or unbranched alcohols with a chain length of from 3 to 30carbon atoms. Such ester oils can then advantageously be chosen from thegroup consisting of octyl palmitate, octyl cocoate, octyl isostearate,octyldodecyl myristate, octyldodecanol, cetearyl isononanoate, isopropylmyristate, isopropyl palmitate, isopropyl stearate, isopropyl oleate,n-butyl stearate, n-hexyl laurate, n-decyl oleate, isooctyl stearate,isononyl stearate, isononyl isononanoate, 2-ethylhexyl palmitate,2-ethylhexyl laurate, 2-hexyldecyl stearate, 2-octyldodecyl palmitate,stearyl heptanoate, oleyl oleate, oleyl erucate, erucyl oleate, erucylerucate, tridecyl stearate, tridecyl trimellitate, and synthetic,semisynthetic and natural mixtures of such esters, such as e.g. jojobaoil.

[0077] The oil phase can also advantageously be chosen from the group ofdialkyl ethers and dialkyl carbonates, advantageous examples beingdicaprylyl ether (Cetiol OE) and/or dicaprylyl carbonate, for examplethat available under the trade name Cetiol CC from Cognis.

[0078] It is also preferred the oil component(s) from the groupconsisting of isoeicosane, neopentyl glycol diheptanoate, propyleneglycol dicaprylate/dicaprate, caprylic/capric/diglyceryl succinate,butylene glycol dicaprylate/dicaprate, C₁₂₋₁₃-alkyl lactate,di-C₁₂₋₁₃-alkyl tartrate, triisostearin, dipentaerythritylhexacaprylate/hexacaprate, propylene glycol monoisostearate,tricaprylin, dimethylisosorbide. It is particularly advantageous if theoil phase of the formulations according to the invention has a contentof C₁₂₋₁₅-alkyl benzoate or consists entirely of this.

[0079] Advantageous oil components are also e.g. butyloctyl salicylate(for example that available under the trade name Hallbrite BHB from CPHall), hexadecyl benzoate and butyloctyl benzoate and mixtures thereof(Hallstar AB).

[0080] Any desired mixtures of such oil and wax components can be usedadvantageously for the purposes of the present invention.

[0081] In addition, the oil phase can likewise advantageously alsocomprise nonpolar oils, for example those chosen from the group ofbranched and unbranched hydrocarbons and hydrocarbon waxes, inparticular mineral oil, vaseline (petrolatum), paraffin oil, squalaneand squalene, polyolefins, hydrogenated polyisobutenes andisohexadecane. Among the polyolefins, polydecenes are the preferredsubstances.

[0082] The oil phase can also advantageously have a content of cyclic orlinear silicone oils or consist entirely of such oils, although it ispreferred to use an additional content of other oil phase componentsapart from the silicone oil or the silicone oils.

[0083] Silicone oils are high molecular weight synthetic polymericcompounds in which silicon atoms are linked in a chain-like and/ornetwork-like manner via oxygen atoms, and the remaining valences of thesilicon are saturated by hydrocarbon radicals (in most cases methyl,less often ethyl, propyl, phenyl groups etc.). Systematically, thesilicone oils are referred to as polyorganosiloxanes. Themethyl-substituted polyorganosiloxanes, which represent the mostsignificant compounds of this group in terms of number and arecharacterized by the following structural formula

[0084] are also referred to as polydimethylsiloxane or Dimethicone(INCI). There are dimethicones with various chain lengths and withvarious molecular weights.

[0085] For the purposes of the present invention, particularlyadvantageous polyorganosiloxanes are, for example, dimethylpolysiloxanes[poly(dimethylsiloxane)], which are available, for example, under thetrade names Abil 10 to 10 000 from Th. Goldschmidt. Also advantageousare phenylmethylpolysiloxanes (INCI: Phenyl Dimethicone, PhenylTrimethicone), cyclic silicones (octamethylcyclotetrasiloxane orDecamethylcyclopentasiloxane), which are also referred to asCyclomethicones in accordance with INCI, amino-modified silicones (INCI:Amodimethicone) and silicone waxes, e.g. polysiloxane-polyalkylenecopolymers (INCI: Stearyl Dimethicone and Cetyl Dimethicone) anddialkoxydimethylpolysiloxanes (Stearoxy Dimethicone and Behenoxy StearylDimethicone), which are available as various Abil wax grades from Th.Goldschmidt. However, for the purposes of the present invention, othersilicone oils can also advantageously be used, for examplecetyldimethicone, hexamethylcyclotrisiloxane, polydimethylsiloxane,poly(methylphenylsiloxane).

[0086] For the purposes of the present invention, it is alsoadvantageous to create cosmetic and dermatological preparations whosemain purpose is not protection against sunlight, but which neverthelesscontain a content of further UV protection substances. Thus, forexample, UV-A and/or UV-B filter substances are usually incorporatedinto day creams or make-up products. UV protection substances, likeantioxidants and, if desired, preservatives, represent effectiveprotection of the preparations themselves against decay. Also favorableare cosmetic and dermatological preparations which are in the form of asunscreen composition.

[0087] Accordingly, the preparations within the meaning of the presentinvention preferably comprise at least one further UV-A, UV-B and/orbroadband filter substance. The formulations may, but do notnecessarily, optionally also comprise one or more organic and/orinorganic pigments as UV filter substances, which may be present in thewater phase and/or the oil phase.

[0088] In addition, the preparations according to the invention canadvantageously also be in the form of so-called oil-free cosmetic ordermatological emulsions, which comprise a water phase and at least oneUV filter substance which is liquid at room temperature and/or one ormore silicone derivatives as the further phase. Oil-free formulationsfor the purpose of the present invention may advantageously alsocomprise further lipophilic components—such as, for example, lipophilicactive ingredients.

[0089] Particularly advantageous UV filter substances which are liquidat room temperature for the purposes of the present invention arehomomenthyl salicylate (INCI: Homosalate), 2-ethylhexyl2-cyano-3,3-diphenylacrylate (INCI: Octocrylene), 2-ethylhexyl2-hydroxybenzoate (2-ethylhexyl salicylate, octyl salicylate, INCI:Octyl Salicylate) and esters of cinnamic acid, preferably4-methoxycinnamic 2-ethylhexyl ester (2-ethylhexyl 4-methoxycinnamate,INCI: Octyl Methoxycinnamate) and 4-methoxycinnamic isopentyl ester(isopentyl 4-methoxycinnamate, INCI: Isoamyl p-Methoxycinnamate).

[0090] Preferred inorganic pigments are metal oxides and/or other metalcompounds which are sparingly soluble or insoluble in water, inparticular oxides of titanium (TiO₂), zinc (ZnO), iron (e.g. Fe₂O₃),zirconium (ZrO₂), silicon (SiO₂), manganese (e.g. MnO), aluminum(Al₂O₃), cerium (e.g. Ce₂O₃), mixed oxides of the corresponding metals,and mixtures of such oxides, and the sulfate of barium (BaSO₄).

[0091] The pigments can advantageously be used for the purposes of thepresent invention also in the form of commercially available oily oraqueous predispersions. Dispersion auxiliaries and/or solubilitypromoters may advantageously be added to these predispersions.

[0092] The pigments may, according to the invention, advantageously besurface-treated (“coated”), the intention being, for example, to form orretain a hydrophilic, amphiphilic or hydrophobic character. This surfacetreatment can consist in providing the pigments with a thin hydrophilicand/or hydrophobic inorganic and/or organic layer by methods known perse. The various surface coatings for the purposes of the presentinvention may also comprise water.

[0093] Inorganic surface coatings for the purposes of the presentinvention may consist of aluminum oxide (Al₂O₃), aluminum hydroxideAl(OH)₃, or aluminum oxide hydrate (also: alumina, CAS No.: 1333-84-2),sodium hexametaphosphate (NaPO₃)₆, sodium metaphosphate (NaPO₃)_(n),silicon dioxide (SiO₂) (also: silica, CAS No.: 7631-86-9), or iron oxide(Fe₂O₃). These inorganic surface coatings may exist on their own, incombination and/or in combination with organic coating materials.

[0094] Organic surface coatings for the purposes of the presentinvention may consist of vegetable or animal aluminum stearate,vegetable or animal stearic acid, lauric acid, dimethylpolysiloxane,(also: dimethicone), methylpolysiloxane (methicone), simethicone (amixture of dimethylpolysiloxane with an average chain length of from 200to 350 dimethylsiloxane units and silica gel) or alginic acid. Theseorganic surface coatings may exist on their own, in combination and/orin combination with inorganic coating materials.

[0095] Zinc oxide particles and predispersions of zinc oxide particleswhich are suitable according to the invention are available under thefollowing trade names from the companies listed: Trade name CoatingManufacturer Z-Cote HP1 2% dimethicone BASF Z-Cote / BASF ZnO NDM 5%dimethicone H&R ZnO Neutral / H&R ZnO MZ 303 M 3% methicone Tayca Corp.

[0096] Suitable titanium dioxide particles and predispersions oftitanium dioxide particles are available under the following trade namesfrom the companies listed: Trade name Coating Manufacturer MT-100TValuminum hydroxide/stearic Tayca Corporation acid MT-100Z aluminumhydroxide/stearic Tayca Corporation acid Eusolex T-2000alumina/simethicone Merck KgaA Titanium dioxide octyltrimethylsilaneDegussa T805 (Uvinul TiO₂) Tioveil AQ alumina/silica Solaveil/ 10PGUniquema

[0097] Further advantageous pigments are latex particles. Latexparticles which are advantageous according to the invention are thosedescribed in the following specifications: U.S. Pat. No. 5,663,213 andEP 0 761 201. Particularly advantageous latex particles are those whichare formed from water and styrene/acrylate copolymers and are available,for example, under the trade name “Alliance SunSphere” from Rohm & Haas.

[0098] Advantageous UV-A filter substances for the purposes of thepresent invention are dibenzoylmethane derivatives, in particular4-(tert-butyl)-4′-methoxydibenzoylmethane (CAS No. 70356-09-1), which issold by Givaudan under the name Parsole 1789 and by Merck under thetrade name Eusolex® 9020.

[0099] Advantageous further UV filter substances for the purposes of thepresent invention are sulfonated, water-soluble UV filters, such as, forexample,

[0100] phenylene-1,4-bis(2-benzimidazyl)-3,3′-5,5′-tetrasulfonic acidand its salts, particularly the corresponding sodium, potassium ortriethanolammonium salts, in particular thephenylene-1,4-bis(2-benzimidazyl)-3,3′-5,5′-tetrasulfonic bis-sodiumsalt with the INCI name Bisimidazylate (CAS No.: 180898-37-7), which isavailable, for example, under the trade name Neo Heliopan AP fromHaarmann & Reimer;

[0101] salts of 2-phenylbenzimidazole-5-sulfonic acid, such as itssodium, potassium or its triethanolammonium salt, and the sulfonic aciditself with the INCI name Phenylbenzimidazole Sulfonic Acid (CAS No.27503-81-7), which is available, for example, under the trade nameEusolex 232 from Merck or under Neo Heliopan Hydro from Haarmann &Reimer;

[0102] 1,4-di(2-oxo-10-sulfo-3-bornylidenemethyl)benzene (also:3,3′-(1,4-phenylene-dimethylene)bis(7,7-dimethyl-2-oxobicyclo[2.2.1]hept-1-ylmethanesulfonic acid) and salts thereof (particularly the corresponding10-sulfato compounds, in particular the corresponding sodium, potassiumor triethanolammonium salt), which is also referred to asbenzene-1,4-di(2-oxo-3-bornylidenemethyl-10-sulfonic acid).Benzene-1,4-di(2-oxo-3-bornylidenemethyl-10-sulfonic acid) has the INCIname Terephthalidene Dicamphor Sulfonic Acid (CAS No.: 90457-82-2) andis available, for example, under the trade name Mexoryl SX from Chimex;

[0103] sulfonic acid derivatives of 3-benzylidenecamphor, such as e.g.4-(2-oxo-3-bornylidenemethyl)benzenesulfonic acid,2-methyl-5-(2-oxo-3-bornylidene-methyl)sulfonic acid and salts thereof.

[0104] Advantageous UV filter substances for the purposes of the presentinvention are also so-called broadband filters, i.e. filter substanceswhich absorb both UV-A- and also UV-B-radiation.

[0105] Advantageous broadband filters or UV-B filter substances are, forexample, triazine derivatives, such as e.g.

[0106] 2,4-bis{[4-(2-ethylhexyloxy)-2-hydroxy]phenyl}-6-(4-methoxyphenyl)-1,3,5-triazine (INCI:Methylene Bis-Benzotriazolmethylbutylphenol), which is available underthe trade name Tinosorb® S from CIBA-Chemikalien GmbH;

[0107] dioctylbutylamidotriazone (INCI: Diethylhexylbutamidotriazone),which is available under the trade name UVASORB HEB from Sigma 3V;

[0108] tris(2-ethyl hexyl)4,4′,4″-(1,3,5-triazine-2,4,6-triyltriimino)trisbenzoate), also:2,4,6-tris[anilino(p-carbo-2′-ethyl-1′-hexyloxy)]-1,3,5-triazine (INCI:Octyl Triazone), which is sold by BASF Aktiengesellschaft under thetrade name UVINUL® T 150.

[0109] An advantageous broadband filter for the purposes of the presentinvention is also2,2′-methylenebis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol) (INCI: Bisoctyltriazole), which is available under thetrade name Tinosorb® M from CIBA-Chemikalien GmbH.

[0110] An advantageous broadband filter for the purposes of the presentinvention is also2-(2H-benzotriazol-2-yl)-4-methyl-6-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propyl]phenol(CAS No.: 155633-54-8) with the INCI name Drometrizole Trisiloxane.

[0111] The further UV filter substances may be oil-soluble. Advantageousoil-soluble filter substances are e.g.:

[0112] 3-benzylidenecamphor derivatives, preferably3-(4-methylbenzylidene)camphor, 3-benzylidenecamphor;

[0113] 4-aminobenzoic acid derivatives, preferably 2-ethylhexyl4-(dimethylamino)benzoate, amyl 4-(dimethylamino)benzoate; derivativesof benzophenone, preferably 2-hydroxy-4-methoxybenzophenone,2-hydroxy-4-methoxy-4′-methylbenzophenone,2,2′-dihydroxy-4-methoxybenzo-phenone

[0114] and UV filters bound to polymers.

[0115] A further photoprotective filter substance to be usedadvantageously according to the invention is ethylhexyl2-cyano-3,3-diphenylacrylate (Octocrylene), which is available from BASFunder the name Uvinul® N 539.

[0116] Particularly advantageous preparations for the purposes of thepresent invention, which may be characterized by a high or very highUV-A protection, comprise, as well as the filter substance(s) accordingto the invention, preferably also further UV-A and/or broadband filters,in particular dibenzoylmethane derivatives [for example4-(tert-butyl)-4′-methoxydibenzoylmethane] and/or2,4-bis{[4-(2-ethylhexyloxy)-2-hydroxylphenyl}-6-(4-methoxyphenyl)-1,3,5-triazine,in each case individually or in any combinations with one another.

[0117] The list of UV filters specified which can be used for thepurposes of the present invention is not of course intended to belimiting.

[0118] Advantageously, the preparations according to the inventioncomprise the substances which absorb UV radiation in the UV-A and/orUV-B region in a total amount of e.g. 0.1% by weight to 30% by weight,preferably 0.5 to 20% by weight, in particular 1.0 to 15.0% by weight,in each case based on the total weight of the preparations, in order toprovide cosmetic preparations which protect the hair and/or the skinfrom the entire range of ultraviolet radiation.

[0119] In addition, it may in some instances be advantageous toincorporate film formers into the cosmetic or dermatologicalpreparations according to the invention, for example in order to improvethe water resistance of the preparations or to increase the UVprotection performance (UV-A and/or UV-B boosting). Water-soluble ordispersible and also fat-soluble film formers are suitable, in each caseindividually or in combination with one another.

[0120] Advantageus water-soluble or dispersible film formers are e.g.polyurethanes (e.g the Avalure® grades from Goodrich), dimethiconecopolyol polyacrylate (Silsoft Surface® from Witco Organo SiliconesGroup), PVPNA (VA=vinyl acetate) copolymer (Luviscol VA 64 Powder fromBASF) etc.

[0121] Advantageous fat-soluble film formers are e.g. the film formersfrom the group of polymers based on polyvinylpyrrolidone (PVP)

[0122] Particular preference is given to copolymers ofpolyvinylpyrrolidone, for example the PVP hexadecene copolymer and thePVP eicosene copolymer, which are available under the trade namesAntaron V216 and Antaron V220 from GAF Chemicals Cooperation and alsotricontayl PVP and the like.

[0123] The examples below serve to illustrate the present inventionwithout limiting it. The numerical values in the examples arepercentages by weight, based on the total weight of the particularpreparations.

EXAMPLES

[0124] 1. O/W sunscreen emulsions 1 2 3 4 5 6 7 Glycerol monostearate SE0.50 1.00 3.00 1.50 Glyceryl stearate citrate 2.00 1.00 2.00 2.50Stearic acid 3.00 2.00 PEG-40 stearate 0.50 2.00 Cetyl dimethiconecopolyol 0.75 0.50 Cetyl phosphate 1.00 Stearyl alcohol 3.00 2.00 0.50Cetyl Alcohol 2.50 1.00 1.50 0.50 2.00 Ethylhexyl 6.00 8.00methoxycinnamate Anisotriazine 1.50 2.50 2.50 2.50Butylmethoxydibenzoylmethane 1.00 3.00 2.80 1.50 Bisimidazylate 0.501.70 Ethylhexyltriazone 4.00 3.00 4.00 2.00 Octocrylene 4.00 2.50Diethylhexylbutamidotriazone 1.00 1.00 Phenylbenzimidazolesulfonic 0.50acid Bioctyltriazole 2.00 0.50 2.50 Homosalate 2.00 Ethylhexylsalicylate 3.00 5.00 Drometrizole trisiloxane 0.5 1.00Terephthalidenedicamphorsulfonic 1.50 1.00 0.50 acid Diethylhexyl2,6-naphthalate 3.50 4.80 7.00 9.50 6.70 5.50 8.00 Titanium dioxideMT-100Z 1.00 3.00 2.00 Zinc oxide NDM 1.50 2.00 3.00 C12-15 alkylbenzoate 2.50 4.00 7.00 5.00 Dicaprylyl ether 3.50 2.00 Butylene glycol5.00 6.00 dicaprylate/dicaprate Dibutyl adipate 6.00 2.00 2.00Dimethicone 0.50 1.00 2.00 Cyclomethicone 2.00 0.50 0.50 Shea butter2.00 0.50 PVP hexadecene copolymer 0.50 0.50 1.00 1.00 Tricontanyl PVP0.50 1.00 1.00 Glycerol 3.00 7.50 7.50 5.00 2.50 Xanthan gum 0.15 0.050.30 Sodium carbomer 0.20 0.10 0.20 Vitamin E acetate 0.50 0.25 0.500.75 1.00 Alpha-glucosylrutin 0.25 0.75 0.20 Ascorbic acid 2.50Panthenol 1.50 5.00 Aloe Vera 1.50 3.50 DMDM hydantoin 0.60 0.40 0.20Konkaben LMB ® 0.18 0.20 0.10 0.15 Methylparaben 0.15 0.25 0.50Phenoxyethanol 1.00 0.40 0.40 0.50 0.40 0.60 EDTA 0.20 0.35 0.50 0.020.03 Iminodisuccinic acid 0.35 0.10 0.10 Ethanol 2.00 1.50 3.00 1.00Perfume 0.20 0.20 0.20 0.20 Water ad 100 ad 100 ad 100 ad 100 ad 100 ad100 ad 100 2. Hydrodispersions 1 2 3 4 5 PEG-40 stearate 1.00 0.5 Cetylalcohol 1.00 Sodium carbomer 0.20 0.30 Acrylates/C10-30 alkyl acrylate0.50 0.40 0.10 0.10 crosspolymer Xanthan gum 0.30 0.15 0.50 Ethylhexylmethoxycinnamate 5.00 8.00 Anisotriazine 2.00 2.50Butylmethoxydibenzoylmethane 0.50 2.00 3.00 2.50 Bisimidazylate 1.503.00 Ethylhexyltriazone 3.00 4.00 Octocrylene 4.00 3.90 2.50Diethyhexylbutamidotriazone 2.00 Phenylbenzimidazolesulfonic 3.00 acidDrometrizole trisiloxane 1.00 1.50 Terephthalidenedicamphorsulfonic 0.501.00 acid Diethylhexyl 2,6-naphthalate 4.50 8.00 7.20 5.50 9.80 Titaniumdioxide MT-100TV 2.00 1.00 Zinc oxide HP1 3.00 C12-15 alkyl benzoate2.00 2.50 Butylene glycol dicaprylate/ 4.00 2.00 6.00 dicaprateDicaprylyl carbonate 2.00 6.00 Dimethicone 0.50 1.00 Shea butter 2.003.50 1.50 PVP hexadecene copolymer 0.50 0.50 1.00 Ethylhexylglycerol1.00 0.50 Glycerol 3.00 7.50 7.50 2.50 Glycine soya 1.50 Vitamin E 0.500.25 1.00 Alpha-glucosylrutin 1.00 0.25 0.75 Ascorbyl palmitate 0.250.65 0.40 DMDM hydantoin 0.60 0.40 0.20 Konkaben LMB ® 0.20 0.15Methylparaben 0.50 0.25 0.15 Phenoxyethanol 0.50 0.40 1.00 0.60Iminodisuccinic acid 0.50 0.35 1.00 Ethanol 3.00 2.00 1.50 1.00 Perfume0.20 0.20 0.20 Water ad 100 ad 100 ad 100 ad 100 ad 100 3. W/O sunscreenemulsions 1 2 3 4 5 Cetyldimethicone copolyol 2.50 4.00 Polyglyceryl-25.00 7.00 dipolyhydroxystearate PEG-30 dipolyhydroxystearate 5.00Laurylmethicone copolyol 3.00 2.00 Ethylhexyl methoxycinnamate 8.00 5.004.00 Anisotriazine 2.50 2.00 2.00 2.50 Butylmethoxydibenzoylmethane 3.001.00 0.70 Bisimidazylate 2.00 2.60 Ethylhexyltriazone 3.00 4.004-Methylbenzylidenecamphor 2.00 4.00 2.00 Octocrylene 2.50 3.90 2.50Diethyhexylbutamidotriazone 2.00 Phenylbenzimidazolesulfonic 3.00 2.00acid Bisoctyltriazole 2.00 0.50 Dimethicone 1.50 0.50diethylbenzalmalonate Drometrizole trisiloxane 1.00 1.50Terephthalidenedicamphorsulfonic 1.00 0.50 acid Diethylhexyl2,6-naphthalate 7.50 5.50 8.50 4.00 12.00 Titanium dioxide T805 2.001.50 3.00 Z-Cote HP1 8.00 2.00 Mineral oil 5.00 10.0 8.00 C12-15 alkylbenzoate 5.00 9.00 Dicaprylyl ether 10.00 7.00 Butylene glycoldicaprylate/ 2.00 8.00 4.00 dicaprate Dicaprylyl carbonate 5.00 6.00Dimethicone 4.00 1.00 5.00 Cyclomethicone 2.00 25.00 2.00 Shea butter2.00 3.00 PVP hexadecene copolymer 0.50 0.50 1.00 Ethylhexylglycerol0.30 1.00 0.50 Glycerol 3.00 7.50 7.50 2.50 Glycine soya 1.00 1.50 MgSO₄1.00 0.50 0.50 Vitamin E acetate 0.50 0.25 1.00 Alpha-glucosylrutin 0.501.00 Aloe Vera 0.15 0.50 4.00 1.50 Biotin 3.00 DMDM hydantoin 0.60 0.400.20 Methylparaben 0.50 0.25 0.15 Phenoxyethanol 0.50 0.40 1.00 0.60EDTA 0.20 0.35 0.15 Ethanol 3.00 6.00 1.00 Perfume 0.20 0.20 0.20 Waterad 100 ad 100 ad 100 ad 100 ad 100 4. Solids-stabilized emulsions 1 2 34 5 Mineral oil 16.0 16.0 Octyldodecanol 9.0 9.0 5.0 Caprylic/caprictriglyceride 9.0 9.0 6.0 C12-15 alkylbenzoate 5.0 8.0 Butylene glycoldicaprylate/ 3.5 8.0 dicaprate Dicaprylyl ether 9.0 4.0 Dicaprylylcarbonate 9.0 Hydroxyoctacosanyl 2.0 2.0 2.0 2.0 1.5 hydroxystearateDisteardimonium hectorite 1.0 0.5 0.5 0.25 Cera Microcristallina +Paraffinum 5.0 Liquidum Hydroxypropylmethylcellulose 0.15 0.05Dimethicone 2.50 3.0 Butylmethoxydibenzoylmethane 0.50 3.50 1.50 0.50Ethylhexyl methoxycinnamate 3.0 Diethylhexylbutamidotriazone 2.50 4.0Bisoctyltriazole 1.00 2.0 Drometrizole trisiloxane 0.50 1.00Terephthalidenedicamphor- 1.00 0.50 1.50 sulfonic acid Bisimidazylate2.00 3.10 1.50 0.50 Eusolex ® T-2000 2.0 4.0 2.0 4.0 Titanium dioxide T805 3.0 Zinc oxide HP1 6.0 Silica dimethyl silylate 1.0 Boron nitride2.0 Starch/sodium metaphosphate 0.5 polymer Diethylhexyl 2,6-naphthalate5.00 7.00 8.50 3.00 4.50 Tapioca starch 1.0 Biotin 0.20 1.50 0.50Alpha-glucosylrutin 1.50 2.00 3.00 Sodium chloride 1.0 1.0 1.0 1.0 1.0Glycerol 5.0 10.0 3.0 6.0 10.0 Trisodium EDTA 1.0 1.0 Methylparaben 0.210.2 Propylparaben 0.07 Phenoxyethanol 0.5 0.4 0.4 0.5 Hexamidinediisethionate 0.08 Diazolidinylurea 0.28 0.28 Alcohol 2.5 Perfume q.s.q.s. q.s. q.s. q.s. Water ad 100 ad 100 ad 100 ad 100 ad 100 5. PITemulsions 1 2 3 4 5 6 7 8 Glycerol monostearate SE 5.50 2.00 3.00 5.000.50 4.00 Glyceryl isostearate 3.50 4.00 2.00 Isoceteth-20 0.50 2.00Ceteareth-12 1.00 5.00 1.00 3.50 Ceteareth-20 4.50 2.00 2.50 3.00PEG-100 stearate 1.00 1.00 0.50 Cetyl alcohol 2.50 1.00 1.50 0.50 1.50Cetyl palmitate 0.50 1.00 Cetyl dimethicone copolyol 0.50 0.50 1.00Polyglyceryl-2 0.75 0.25 dipolyhydroxystearate Diethylhexyl2,6-naphthalate 7.0 3.5 1.0 6.0 0.5 4.0 5.0 4.5 Anisotriazine 0.50 2.003.00 Butylmethoxydibenzoylmethane 1.00 5.00 Bisimidazylate 2.00 1.00Terephthalidenedicamphorsulfonic 0.50 1.00 acid Drometrizole trisiloxane2.00 3.00 1.00 Ethylhexyl methoxycinnamate 4.50 5.00 8.00 Ethylhexylsalicylate 3.50 4.00 Dioctylbutamidotriazone 3.00 2.00 2.00 1.50Ethylhexyltriazone 2.00 4.00 1.50 3.00 Dimethicone 4.50 3.50diethylbenzalmalonate Octocrylene 5.00 8.00 7.50Phenylbenzimidazolesulfonic 5.00 3.00 1.00 acid C12-15 alkyl benzoate3.50 6.50 4.00 Cocoglycerides 3.00 3.00 2.50 3.50 Dicaprylyl ether 4.00Butylene glycol dicaprylate/ 4.00 3.00 dicaprate Dicaprylyl carbonate0.50 6.00 Dibutyl adipate 2.50 3.00 1.00 Cyclomethicone 3.00 4.00 PVPhexadecene copolymer 1.00 1.50 Glycerol 10.0 5.00 7.50 Tocopherol 1.000.75 0.50 1.00 0.25 Alpha-glucosylrutin 0.45 0.50 1.00 0.25 0.15Hammamelis extract 5.00 10.00 4.50 Aloe Vera 5.00 2.50 Shea butter 2.000.50 Iodopropyl butylcarbamate 0.12 0.20 0.15 DMDM hydantoin 0.10Methylparaben 0.50 0.25 0.45 Phenoxyethanol 0.50 0.40 1.00 1.00Octoxyglycerol 0.30 1.00 Ethanol 2.00 7.50 4.00 Trisodium EDTA 0.40 0.150.20 0.50 Perfume 0.20 0.20 0.20 0.45 0.20 Water ad 100 ad 100 ad 100 ad100 ad 100 ad 100 ad 100 ad 100

That which is claimed:
 1. A cosmetic or dermatological formulation,comprising: at least one hydrophilic active ingredient, and at least onedialkyl naphthalate which is characterized by the structural formula

in which R¹ and R², independently of one another, are selected from thegroup consisting of branched and unbranched alkyl groups having 6 to 24carbon atoms.
 2. The formulation as claimed in claim 1, wherein the atleast one dialkyl naphthalate is present in an amount from 0.001 to 30%by weight, based on the total weight of the preparation.
 3. Theformulation as claimed in claim 1, wherein the at least one dialkylnaphthalate is present in an amount from 0.01 to 20% by weight, based onthe total weight of the preparation.
 4. The formulation as claimed inclaim 1, wherein the at least one dialkyl naphthalate is present in anamount from 1 to 15% by weight, based on the total weight of thepreparation.
 5. The formulation as claimed in claim 1, wherein at leastone of R¹ and R² is a branched alkyl group having 6 to 10 carbon atoms.6. The formulation as claimed in claim 1, wherein R¹ and R² are branchedalkyl groups having 6 to 10 carbon atoms.
 7. The formulation as claimedin claim 1, wherein the at least one dialkyl naphthalate includesdiethylhexyl naphthalate.
 8. The formulation as claimed in claim 1,wherein the at least one hydrophilic active ingredient is present in anamount from 0.0001 to 10% by weight, based on the total weight of thepreparation.
 9. The formulation as claimed in claim 1, wherein the atleast one hydrophilic active ingredient is present in an amount from0.001 to 5% by weight, based on the total weight of the preparation. 10.The formulation as claimed in claim 1, wherein the at least onehydrophilic active ingredient is selected from the group consisting ofbiotin, carnitine and derivatives thereof, creatine and derivativesthereof, folic acid, pyridoxine, niacinamide, polyphenols, ascorbic acidand derivatives thereof, Hamamelis, Aloe Vera, panthenol and aminoacids.
 11. The formulation as claimed in claim 10, wherein the at leastone hydrophilic active ingredient includes an active ingredient selectedfrom the group consisting of biotin, carnitine, flavonoids, and ascorbicacid.
 12. The formulation as claimed in claim 10, wherein the at leastone hydrophilic active ingredient includes a polyphenol and thepolyphenol is a flavonoid.
 13. The formulation as claimed in claim 12,wherein the flavonoid is alpha-glucosylrutin.
 14. The formulation asclaimed in claim 1, further comprising at least one UV filter substanceselected from the group consisting of triazines, benzotriazoles, UVfilters which are liquid at room temperature, organic pigments andinorganic pigments.
 15. The formulation as claimed in claim 1, furthercomprising at least one fat-soluble active ingredient.
 16. Theformulation as claimed in claim 15, wherein the at least one fat-solubleactive ingredient includes vitamin E or a vitamin E derivative.
 17. Theformulation as claimed in claim 16, wherein the vitamin E or a vitamin Ederivative is present in an amount from 0.001 to 10% by weight, based onthe total weight of the preparation.
 18. The formulation as claimed inclaim 15, wherein the at least one fat-soluble active ingredientincludes an active ingredient selected from the group consisting ofvitamin A, vitamin A derivatives, carotene and carotene derivatives. 19.The formulation as claimed in claim 18, wherein the active ingredientselected from the group consisting of vitamin A, vitamin A derivatives,carotene and carotene derivatives is present in an amount from 0.001 to10% by weight, based on the total weight of the preparation.
 20. Theformulation as claimed in claim 1, further comprising at least oneactive ingredient selected from the group consisting of ubiquinones,retinoids, caroretinoids, creatine, taurine and β-alanine.
 21. Theformulation as claimed in claim 1, futher comprising at least one UV-Afilter substance or one broadband filter selected from the groupconsisting of 4-(tert-butyl)-4′-methoxydibenzoylmethane;2,4-bis{[4-(2-ethy]hexyloxy)-2-hydroxy]phenyl}-6-(4-methoxyphenyl)-1,3,5-triazine,phenylene-1,4-bis(2-benzimidazyl)-3,3′-5,5′-tetra-sulfonic acidbis-sodium salt, and mixtures thereof.
 22. The formulation as claimed inclaim 1, wherein the formulation is an oil-in-water emulsion.
 23. Theformulation as claimed in claim 22, wherein the oil-in-water emulsion isa sunscreen emulsion and further comprises at least one UV filtersubstance, said at least one dialkyl naphthalate being present in anamount from 3.5 to 9.5% by weight, based on the total weight of thepreparation.
 24. The formulation as claimed in claim 22, wherein theoil-in-water emulsion is a sunscreen emulsion and further comprises atleast one UV filter substance, said at least one dialkyl naphthalatebeing diethylhexyl naphthalate and present in an amount from 1 to 15% byweight, based on the total weight of the preparation.
 25. Theformulation as claimed in claim 1, wherein the formulation is ahydrodispersion.
 26. The formulation as claimed in claim 25, whereinsaid at least one dialkyl naphthalate is present in an amount from 4.5to 9.8% by weight, based on the total weight of the preparation.
 27. Theformulation as claimed in claim 25, wherein said at least one dialkylnaphthalate is diethylhexyl naphthalate and is present in an amount from1 to 15% by weight, based on the total weight of the preparation. 28.The formulation as claimed in claim 1, wherein the formulation is anwater-in-oil emulsion.
 29. The formulation as claimed in claim 28,wherein the water-in-oil emulsion is a sunscreen emulsion and furthercomprises at least one UV filter substance, said at least one dialkylnaphthalate being present in an amount from 4.0 to 12.0% by weight,based on the total weight of the preparation.
 30. The formulation asclaimed in claim 28, wherein the water-in-oil emulsion is a sunscreenemulsion and further comprises at least one UV filter substance, said atleast one dialkyl naphthalate being diethylhexyl naphthalate and presentin an amount from 1 to 15% by weight, based on the total weight of thepreparation.
 31. The formulation as claimed in claim 1, wherein theformulation is a solids stabilized emulsion.
 32. The formulation asclaimed in claim 31, wherein said at least one dialkyl naphthalate beingpresent in an amount from 3.0 to 8.5% by weight, based on the totalweight of the preparation.
 33. The formulation as claimed in claim 31,wherein said at least one dialkyl naphthalate is diethylhexylnaphthalate and present in an amount from 1 to 15% by weight, based onthe total weight of the preparation.
 34. The formulation as claimed inclaim 1, wherein the formulation is a PIT emulsion.
 35. The formulationas claimed in claim 34, wherein said at least one dialkyl naphthalatebeing present in an amount from 0.5 to 7.0% by weight, based on thetotal weight of the preparation.
 36. The formulation as claimed in claim34, wherein said at least one dialkyl naphthalate is diethylhexylnaphthalate and present in an amount from 1 to 15% by weight, based onthe total weight of the preparation.
 37. A cosmetic or dermatologicalformulation, comprising: at least one hydrophilic active ingredientselected from the group consisting of biotin, carnitine and derivativesthereof, creatine and derivatives thereof, folic acid, pyridoxine,niacinamide, polyphenols, ascorbic acid and derivatives thereof,Hamamelis, Aloe Vera, panthenol and amino acids, in an amount from 0.001to 5% by weight, based on the total weight of the preparation, anddiethylhexyl naphthalate in an amount from 1 to 15% by weight, based onthe total weight of the preparation.
 38. A method for moisturizing skin,comprising the step of applying to the skin a cosmetic or dermatologicalformulation, comprising at least one hydrophilic active ingredient andat least one dialkyl naphthalate which is characterized by thestructural formula

in which R¹ and R², independently of one another, are selected from thegroup consisting of branched and unbranched alkyl groups having 6 to 24carbon atoms.
 39. A method for protecting the skin against photoinducedskin aging, comprising the step of applying to the skin a cosmetic ordermatological formulation, comprising at least one hydrophilic activeingredient and at least one dialkyl naphthalate which is characterizedby the structural formula

in which R¹ and R², independently of one another, are selected from thegroup consisting of branched and unbranched alkyl groups having 6 to 24carbon atoms.
 40. A method for improving the effectiveness ofhydrophilic active ingredients in cosmetic or dermatologicalpreparations, said method comprising adding to the cosmetic ordermatological formulation at least one dialkyl naphthalate which ischaracterized by the structural formula

in which R¹ and R², independently of one another, are chosen from thegroup of branched and unbranched alkyl groups having 6 to 24 carbonatoms.
 41. A method for increasing the stability of hydrophilic activeingredients against decomposition in cosmetic or dermatologicalpreparations, said method comprising adding to the cosmetic ordermatological formulation at least one dialkyl naphthalate which ischaracterized by the structural formula

in which R¹ and R², independently of one another, are chosen from thegroup of branched and unbranched alkyl groups having 6 to 24 carbonatoms.